* {
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #0d0d0d;
    padding: 20px;
}

.container{
  width: 90%;
  max-width: 360px;
}

.card {
    width: 100%;
    height: 220px;
    perspective: 1200px;
    margin-bottom: 22px;
}

.card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.8s;
}

.card-front,
.card-back {
    position: absolute;
    inset: 0;
    border-radius: 18px;
    padding: 20px;
    backface-visibility: hidden;
}

.card-front {
    background: linear-gradient(120deg, #374a57, #4b4f8c, #6a3db8);
    color: white;
}

.card-back {
    background: #2a2a2a;
    transform: rotateY(180deg);
}

.chip {
    margin-top: 25px;
    width: 52px;
    height: 40px;
}

.card-number {
    margin-top: 35px;
    font-size: 20px;
    letter-spacing: 3px;
    font-weight: bold;
    margin-bottom: 22px;
}

.card-details {
    display: flex;
    justify-content: space-between;
}

.stripe {
    height: 42px;
    background: black;
    margin-top: 10px;
}

.cvv {
    margin-top: 32px;
    background: white;
    color: black;
    padding: 10px;
    text-align: right;
    font-weight: bold;
}

form {
    background: white;
    padding: 20px;
    border-radius: 14px;
}

.inputBox {
    margin-bottom: 15px;
}

.inputBox span {
    display: block;
    margin-bottom: 6px;
}

.inputBox input,
.inputBox select {
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

.flex {
    display: flex;
    gap: 10px;
}

@media (max-width: 500px){
    body{
        align-items: flex-start;
        padding-top: 30px;
    }

    .flex{
        flex-direction: column;
        gap: 12px;
    }

    .card-number{
        font-size: 18px;
        letter-spacing: 2px;
    }

    .card-details{
        font-size: 12px;
    }

    .chip{
        margin-top: 15px;
    }
}